The goal of this study is to provide an integrative analysis of Sumerian magico-religious practices with special attention paid to demonology and to the Mesopotamian concept of evil. A synthetic approach will help to assess the state of Mesopotamian demonological research, to demonstrate why the so-called “magical” ideas of an ancient civilization are essential to understanding humanity, and to suggest a path forward with “evil” as a lens for historical and cultural understanding. This will be attempted in five phases: first, the terms “magic” and “demons” must be reclaimed as historically useful and contextually appropriate to the Sumerian worldview. Next, we briefly survey how the Sumerians and ancient Mesopotamians understood and participated in magic. Then, we examine the role of demons in the Mesopotamian magical worldview. With this understanding, we write a biography of one demon, Lamaštu, as a case study. Lamaštu played a dominant role in Sumerian magico-religious and magico-medical practices and there is sufficient research to compile a biography for her. Then, Lamaštu is reintegrated into the Sumerian pantheon of demons as an exemplum for further studies.